目的 了解临床分离阴沟肠杆菌膜孔蛋白基因缺失合并β-内酰胺酶和Ⅰ类整合子所致耐药的特点及其分布.方法 收集2008年1月至2011年5月自临床感染患者分离的112株阴沟肠杆菌.应用vitek-2 compact鉴定细菌,k-b法进行药敏试验,改良hodge试...目的 了解临床分离阴沟肠杆菌膜孔蛋白基因缺失合并β-内酰胺酶和Ⅰ类整合子所致耐药的特点及其分布.方法 收集2008年1月至2011年5月自临床感染患者分离的112株阴沟肠杆菌.应用vitek-2 compact鉴定细菌,k-b法进行药敏试验,改良hodge试验、美罗培南改良三维实验和edta-美罗培南纸片协同试验筛选产碳青霉烯酶菌株.多重pcr分别检测4种esbls基因、6种ampc酶基因、4种碳青霉烯酶基因及4组oxa-like基因,单一pcr检测isecpl、ompk35/36、ndm-1、oxa-48,并对Ⅰ类整合子可变区进行pcr扩增及序列分析.结果 6株(5.4％)改良hodge试验阳性,14株(12.5％)美罗培南改良三维试验阳性,未检出碳青霉烯酶基因.29株(25.9％)esbls基因阳性,其中,ctx-m基因上游均检测到isecpl,并检测到2株产oxa-1型esbls阴沟肠杆菌.ampc酶基因阳性45株(40.2％),以mir-3型为主(37/45,82.2％).共检出22株Ⅰ类整合子基因阳性菌株,其中16株可变区扩增阳性.扩增出4种耐药基因盒,aadb-aada2(1 000 bp)9株,dfra 15 (700 bp)5株,aadal(1 000 bp)2株,有l株菌同时携带4种耐药基因盒.所有菌株均合并有膜孔蛋白ompk35和/或ompk36基因缺失,并呈现多重耐药.结论 阴沟肠杆菌对碳青霉烯类抗生素的敏感性降低主要与其高产ampc酶、esbls并存在膜孔蛋白ompk35和/或ompk36基因缺失有关,且Ⅰ类整合子参与阴沟肠杆菌的多重耐药.
abstract：
objective to investigate the drug resistance and its distribution induced by β-lactamases and class Ⅰ integrons with the deficiency of omp genes in enterobacter cloacaes.methods totally 112 strains of enterobacter cloacaes were isolated during january 2008 and may 2011.the identification of strains was performed by using vitek-2 compact automatic system; and antibiotic susceptibility was determined by k-b method.isolates of e.cloacae were screened for carbapenemases by modified hodge test,improved three dimensional test and edta-meropenem synergy test.genes encoding ampc β-lactamase,metallo-β-1actamases (mbls) and oxa-like β-1actamases were screened by multiple pcr.single pcr was used to detect isecpl,ompk35/36,ndm-1 and oxa-48.the variable regions of class Ⅰ integrons were amplified and sequenced.results among 112 isolates,6 (5.4％) demonstrated positive in the modified hodge test and 14 ( 12.5％ ) were positive in the improved three-dimensional test.no carbapenemases gene was found.there were 29(25.9％ ) strains positive for esbls genes,isecpl was found in the upstream of all the ctx-m-type esbls; oxa-1 esbls were detected in 2 isolates.ampc β-lactamase genes were positive in 45 (40.2％) strains,and 82.2％ (37/45) were mir-3 type.twenty two isolates carried class Ⅰ integrons,and four different cassettes arrangements were identified within 16 strains:9 isolates harbored aadb-aada2 ( 1 000 bp),5 isolates with dfral5 (700 bp),2 isolates with aadal ( 1 000 bp).one isolate harbored all the above gene cassettes.the deficiency of ompk35/36 was found in all strains.conclusion esbl,ampc β-lactamase and the deficiency of ompk35/36 are correlated with the resistance to carbapenems in enteobacter clocace,and class Ⅰ integrons may also partly account for the multidrug-resistance.展开更多
文摘目的 了解临床分离阴沟肠杆菌膜孔蛋白基因缺失合并β-内酰胺酶和Ⅰ类整合子所致耐药的特点及其分布.方法 收集2008年1月至2011年5月自临床感染患者分离的112株阴沟肠杆菌.应用vitek-2 compact鉴定细菌,k-b法进行药敏试验,改良hodge试验、美罗培南改良三维实验和edta-美罗培南纸片协同试验筛选产碳青霉烯酶菌株.多重pcr分别检测4种esbls基因、6种ampc酶基因、4种碳青霉烯酶基因及4组oxa-like基因,单一pcr检测isecpl、ompk35/36、ndm-1、oxa-48,并对Ⅰ类整合子可变区进行pcr扩增及序列分析.结果 6株(5.4％)改良hodge试验阳性,14株(12.5％)美罗培南改良三维试验阳性,未检出碳青霉烯酶基因.29株(25.9％)esbls基因阳性,其中,ctx-m基因上游均检测到isecpl,并检测到2株产oxa-1型esbls阴沟肠杆菌.ampc酶基因阳性45株(40.2％),以mir-3型为主(37/45,82.2％).共检出22株Ⅰ类整合子基因阳性菌株,其中16株可变区扩增阳性.扩增出4种耐药基因盒,aadb-aada2(1 000 bp)9株,dfra 15 (700 bp)5株,aadal(1 000 bp)2株,有l株菌同时携带4种耐药基因盒.所有菌株均合并有膜孔蛋白ompk35和/或ompk36基因缺失,并呈现多重耐药.结论 阴沟肠杆菌对碳青霉烯类抗生素的敏感性降低主要与其高产ampc酶、esbls并存在膜孔蛋白ompk35和/或ompk36基因缺失有关,且Ⅰ类整合子参与阴沟肠杆菌的多重耐药.
abstract：
objective to investigate the drug resistance and its distribution induced by β-lactamases and class Ⅰ integrons with the deficiency of omp genes in enterobacter cloacaes.methods totally 112 strains of enterobacter cloacaes were isolated during january 2008 and may 2011.the identification of strains was performed by using vitek-2 compact automatic system; and antibiotic susceptibility was determined by k-b method.isolates of e.cloacae were screened for carbapenemases by modified hodge test,improved three dimensional test and edta-meropenem synergy test.genes encoding ampc β-lactamase,metallo-β-1actamases (mbls) and oxa-like β-1actamases were screened by multiple pcr.single pcr was used to detect isecpl,ompk35/36,ndm-1 and oxa-48.the variable regions of class Ⅰ integrons were amplified and sequenced.results among 112 isolates,6 (5.4％) demonstrated positive in the modified hodge test and 14 ( 12.5％ ) were positive in the improved three-dimensional test.no carbapenemases gene was found.there were 29(25.9％ ) strains positive for esbls genes,isecpl was found in the upstream of all the ctx-m-type esbls; oxa-1 esbls were detected in 2 isolates.ampc β-lactamase genes were positive in 45 (40.2％) strains,and 82.2％ (37/45) were mir-3 type.twenty two isolates carried class Ⅰ integrons,and four different cassettes arrangements were identified within 16 strains:9 isolates harbored aadb-aada2 ( 1 000 bp),5 isolates with dfral5 (700 bp),2 isolates with aadal ( 1 000 bp).one isolate harbored all the above gene cassettes.the deficiency of ompk35/36 was found in all strains.conclusion esbl,ampc β-lactamase and the deficiency of ompk35/36 are correlated with the resistance to carbapenems in enteobacter clocace,and class Ⅰ integrons may also partly account for the multidrug-resistance.
